Modified directional effect

Abstract

An example method is performed by a media playback system comprising a plurality of audio drivers configured to output audio content according to a first radiation pattern that produces an inherent directional effect. Based on data indicating characteristics of a listening area in which the media playback system operates, the system determines first and second transfer functions corresponding to the first and second audio drivers, respectively. One or both of the transfer functions configure the first and second audio drivers to output audio content according to a second radiation pattern that produces a modified directional effect relative to the first radiation pattern. The system applies the transfer function to audio content thereby causing the first and second audio drivers to play back audio content according to the second radiation pattern.

We claim: 
     
       1. A media playback system comprising:
 a processor; 
 a network interface; 
 a first audio driver and a second audio driver, wherein the first and second audio drivers are configured to output audio content according to a first radiation pattern that produces an inherent directional effect; and 
 a non-transitory computer-readable medium storing instructions that, when executed by the processor, cause the media playback system to perform operations comprising:
 receiving, via the network interface, first data and second data representing first and second channels, respectively, of multi-channel audio content, wherein the first and second data comprises audio data over a range of frequencies; 
 receiving third data indicating one or more characteristics of a listening area in which the media playback system operates; 
 determining, based on the third data, a first transfer function corresponding to the first audio driver and a second transfer function corresponding to the second audio driver, wherein at least one of the first and second transfer functions configure the first and second audio drivers to output audio content according to a second radiation pattern that produces a modified directional effect relative to the first radiation pattern; 
 generating a first audio output signal and a second audio output signal, wherein generating the first audio output signal comprises applying the first transfer function to the first and second data, and wherein generating the second audio output signal comprises applying the second transfer function to the first and second data; and 
 providing the first audio output signal to the first audio driver and the second audio output signal to the second audio driver, thereby causing the first and second audio drivers to play back the multi-channel audio content according to the second radiation pattern. 
 
 
     
     
       2. The media playback system of  claim 1 , wherein determining the first transfer function further comprises determining the first transfer function based on one or more of (i) a radiation pattern of the first audio driver, (ii) an orientation of the first audio driver with respect to the listening area, and (iii) a position of the first audio driver with respect to the listening area. 
     
     
       3. The media playback system of  claim 1 ,
 wherein the first transfer function is a frequency-dependent transfer function, and 
 wherein generating the first audio output signal further comprises applying the first transfer function to the first and second data to determine a new amplitude corresponding to the first and second data. 
 
     
     
       4. The media playback system of  claim 1 ,
 wherein the first transfer function is a first frequency-dependent transfer function, and 
 wherein generating the first audio output signal further comprises applying the first transfer function to the first and second data to determine a phase offset corresponding to the first and second data. 
 
     
     
       5. The media playback system of  claim 1 , wherein providing the first and second audio output signals to the first and second audio drivers, respectively, comprises, providing corresponding first and second analog signals to input terminals of the first and second audio drivers, respectively. 
     
     
       6. The media playback system of  claim 1 , further comprising:
 a playback device housing the first and second audio drivers, wherein the operations further comprise:
 receiving a command to play back the first channel of the multi-channel audio content; and 
 based on receiving the command, playing back, via the playback device, the first channel of the multi-channel audio content. 
 
 
     
     
       7. The media playback system of  claim 1 , further comprising:
 a first playback device housing the first audio driver; and 
 a second device housing the second audio driver, wherein the operations further comprise:
 causing the first audio driver to play back the first channel of the multi-channel audio content in synchrony with the second audio driver playing back the second channel of the multi-channel audio content. 
 
 
     
     
       8. The media playback system of  claim 1 , further comprising:
 a first playback device comprising a sensor configured to output sensor data, wherein the third data comprises the sensor data; and 
 a second playback device, wherein the sensor data indicates a location of the first playback device relative to the second playback device. 
 
     
     
       9. The media playback system of  claim 1 , further comprising
 a first playback device comprising an accelerometer configured to output sensor data, wherein the third data comprises the sensor data, and wherein the sensor data indicates an orientation of the first playback device. 
 
     
     
       10. The media playback system of  claim 1 , the operations further comprising:
 generating, via at least one of the first audio driver and the second audio driver, an outgoing sound wave that propagates through the listening area; and 
 detecting reflections generated by the outgoing sound wave reflecting from one or more objects of the listening area, wherein the third data includes data indicative of the detected reflections. 
 
     
     
       11. A method for providing audio content having a second radiation pattern, the method performed by a media playback system comprising a network interface, a first audio driver, and a second audio driver, the first and second audio drivers configured to output audio content according to a first radiation pattern that produces an inherent directional effect, the method comprising:
 receiving, via the network interface, first data and second data representing first and second channels, respectively, of multi-channel audio content, wherein the first and second data comprises audio data over a range of frequencies; 
 receiving third data indicating one or more characteristics of a listening area in which the media playback system operates; 
 determining, based on the third data, a first transfer function corresponding to the first audio driver and a second transfer function corresponding to the second audio driver, wherein at least one of the first and second transfer functions configure the first and second audio drivers to output audio content according to a second radiation pattern that produces a modified directional effect relative to the first radiation pattern; 
 generating a first audio output signal and a second audio output signal, wherein generating the first audio output signal comprises applying the first transfer function to the first and second data, and wherein generating the second audio output signal comprises applying the second transfer function to the first and second data; and 
 providing the first audio output signal to the first audio driver and the second audio output signal to the second audio driver, thereby causing the first and second audio drivers to play back the multi-channel audio content according to the second radiation pattern. 
 
     
     
       12. The method of  claim 11 ,
 wherein the first transfer function is a first frequency-dependent transfer function, and 
 wherein generating the first audio output signal further comprises applying the first transfer function to the first and second data to determine a phase offset corresponding to the first and second data. 
 
     
     
       13. The method of  claim 11 , wherein the media playback system comprises:
 a playback device housing the first and second audio drivers, wherein the method further comprises:
 receiving a command to play back the first channel of the multi-channel audio content; and 
 based on receiving the command, playing back, via the playback device, the first channel of the multi-channel audio content. 
 
 
     
     
       14. The method of  claim 11 , wherein the media playback system further comprises:
 a first playback device housing the first audio driver; and 
 a second device housing the second audio driver, wherein the method further comprises:
 causing the first audio driver to play back the first channel of the multi-channel audio content in synchrony with the second audio driver playing back the second channel of the multi-channel audio content. 
 
 
     
     
       15. The method of  claim 11 , further comprising:
 generating, via at least one of the first audio driver and the second audio driver, an outgoing sound wave that propagates through the listening area; and 
 detecting reflections generated by the outgoing sound wave reflecting from one or more objects of the listening area, wherein the third data includes data indicative of the detected reflections. 
 
     
     
       16. A non-transitory computer-readable medium storing instructions that, when executed by a media playback system comprising a network interface, a first audio driver, and a second audio driver, the first and second audio drivers configured to output audio content according to a first radiation pattern that produces an inherent directional effect, cause the media playback system to perform functions comprising:
 receiving, via the network interface, first data and second data representing first and second channels, respectively, of multi-channel audio content, wherein the first and second data comprises audio data over a range of frequencies; 
 receiving third data indicating one or more characteristics of a listening area in which the media playback system operates; 
 determining, based on the third data, a first transfer function corresponding to the first audio driver and a second transfer function corresponding to the second audio driver, wherein at least one of the first and second transfer functions configure the first and second audio drivers to output audio content according to a second radiation pattern that produces a modified directional effect relative to the first radiation pattern; 
 generating a first audio output signal and a second audio output signal, wherein generating the first audio output signal comprises applying the first transfer function to the first and second data, and wherein generating the second audio output signal comprises applying the second transfer function to the first and second data; and 
 providing the first audio output signal to the first audio driver and the second audio output signal to the second audio driver, thereby causing the first and second audio drivers to play back the multi-channel audio content according to the second radiation pattern. 
 
     
     
       17. The non-transitory computer-readable medium of  claim 16 ,
 wherein the first transfer function is a first frequency-dependent transfer function, and 
 wherein generating the first audio output signal further comprises applying the first transfer function to the first and second data to determine a phase offset corresponding to the first and second data. 
 
     
     
       18. The non-transitory computer-readable medium of  claim 16 , wherein the media playback system comprises:
 a playback device housing the first and second audio drivers, wherein the functions further comprise:
 receiving a command to play back the first channel of the multi-channel audio content; and 
 based on receiving the command, playing back, via the playback device, the first channel of the multi-channel audio content. 
 
 
     
     
       19. The non-transitory computer-readable medium of  claim 16 , wherein the media playback system further comprises:
 a first playback device housing the first audio driver; and 
 a second device housing the second audio driver, wherein the functions further comprise:
 causing the first audio driver to play back the first channel of the multi-channel audio content in synchrony with the second audio driver playing back the second channel of the multi-channel audio content. 
 
 
     
     
       20. The non-transitory computer-readable medium of  claim 16 , wherein the functions further comprise:
 generating, via at least one of the first audio driver and the second audio driver, an outgoing sound wave that propagates through the listening area; and 
 detecting reflections generated by the outgoing sound wave reflecting from one or more objects of the listening area, wherein the third data includes data indicative of the detected reflections.